I've been noticing some major distros are now moving into glibc-2.16 territory, such as Arch & Arch-Bang, Mageia, Fedora, Opensuse, and even Linux From Scratch -7.2.

I realize glibc is a major, major toolchain component, but after seeing that 2.16 resolves over 270 bugs and the "stable" Glibc-2.16 was released 6/30/12 I was curious as to when we could expect a first move 2.16, and what implications and/or potential problems could we expect. I know it shouldn't be rushed, just curious as to what difficulties to expect, if any.

The GNU C Library is used as *the* C library in the GNU systems
and most systems with the Linux kernel.

The GNU C Library is primarily designed to be a portable
and high performance C library. It follows all relevant
standards including ISO C99 and POSIX.1-2008. It is also
internationalized and has one of the most complete
internationalization interfaces known.

+ aligned_alloc. NB: The code is deliberately allows the size parameter
to not be a multiple of the alignment. This is a moronic requirement
in the standard but it is only a requirement on the caller, not the
implementation.

* New configure option --enable-obsolete-rpc makes the deprecated RPC
headers and functions available at compile time as they were before
version 2.14. This option will be removed at some time in the future
after the TI-RPC library becomes fully sufficient for the needs of
existing applications.

* Compatibility code for Linux kernel versions before 2.4 has been removed.
Note that glibc is not expected to work with any Linux kernel version
before 2.6.

* New header <sys/auxv.h> and function getauxval allowing easy access to
the AT_* key-value pairs passed from the Linux kernel. The header also
defines the HWCAP_* bits associated with the AT_HWCAP key.

* New locales: mag_IN

* New configure option --enable-systemtap builds SystemTap static probes
into libc for setjmp and longjmp and into libpthread for various operations.
So far the setjmp/longjmp probes and some of the libpthread probes are
provided only for i*86 and x86_64.
Implemented by Roland McGrath and Rayson Ho.

* More optimized functions for PowerPC. Implemented by Adhemerval Zanella
and Will Schmidt.

* More optimized functions for SPARC. Implemented by David S. Miller.

* Improved support for cross-compilation, especially bootstrap builds
without a previously built glibc.

* Ports for the TILE-Gx and TILEPro families of processors. Contributed by
Chris Metcalf from Tilera.

* Support for the old ARM ABI has been removed from ports. Only the EABI is
now supported for ARM processors.

* The hard-float variant of the ARM EABI now uses /lib/ld-linux-armhf.so.3
as the name of the dynamic linker, to distinguish it from the
/lib/ld-linux.so.3 dynamic linker used for the base EABI.

* Support for CRIS has been removed from ports.

* A new class of installed header has been documented for low-level
platform-specific functionality. PowerPC added the first instance with a
function to provide time base register access. Contributed by Tulio
Magno Quites Machado Filho.

* ix86 configurations now install header files that are consistent with
what x86-64 configurations install. These same header files can be used
for -m32, -m64, or -mx32 builds.
Contributed by H.J. Lu.

* Math library bug fixes. A thorough audit of all open math library bugs was
conducted by Joseph Myers. Significant progress was made on many math
library bugs resulting in more accurate exceptions and function results.
Many thanks to all those that contributed including Andreas Jaeger for his
patch review and work on the x87 trigonometric instruction issues.

* Timezone data is no longer installed. Timezone-related binaries and scripts
will continue to be installed. Users should obtain their timezone data from
their distribution provider or from the tzdata package at
<ftp://munnari.oz.au/pub/>.QA

You mistake bug counter as a proof of stability.
Seen x32 ABI support i'm not surprise that bug counter is that high. Just like gentoo bug system, not all bugs are "real one". A "i want portage to output only black & white" query close is a bug close.

The real question would be what would you want from that version? Introduction of a new ABI is certainly not a proof of a less buggy version, i would expect of worst (but that's just a feeling).
For someone wishing x32 of course this is a must have and critical version to get

But i must admit i'm way too conservative with my toolchain, but glibc always scare me bad, as it affect 90% of installed programs health.

Anyway, here is the glibc-2.16 tracker that might be of interest to you: https://bugs.gentoo.org/show_bug.cgi?id=glibc-2.16
Since it is non-keyworded, it hasn't enjoyed a lot of testing yet, so the relatively small amount of bugs there might be misleading. Another biggie is the dependence on boost-1.50 stabilisation which doubles the amount of bugs. You could improve the situation/populate the tracker though with a chroot _________________backend.cpp:92:2: warning: #warning TODO - this error message is about as useful as a cooling unit in the arctic

As far as I understand 2.16 glibs is necessary to run on Tilera Tile Gx and TilePro processors. I can see 2.16 masked as testing (at le ast for x86_64) , so it should be possible to compile it using crossdev or manually for Tilera.

slightly off topic: there is a script on github to crosscompile 2.16 for Tilera here: